The present invention relates to conductive circuits and, more particularly, to novel high density electronic circuits having very narrow conductors arranged in at least one plane therein, and to novel methods for fabricating the very narrow conductors of the circuit.
Many electronic circuits utilize a "sandwich" arrangement having layers of thick film conductors with insulative layers spaced therebetween, to provide a means of interconnecting the various electronic components, including integrated circuits and discrete electronic components, of the circuit. Present technology utilizes screen printing of a mask pattern to define the conductive paths, and the interlayer via connections between conductive paths in the various planes. Presently, line widths less than about 4 milli-inches can not practically be provided with screen printing techniques, thereby establishing an upper limit on the density of circuit interconnects. In devices such as hybrid circuit modules, optoelectronic displays and similar electronic circuits which require a high interconnect density, but which are not amenable to integrated circuit manufacturing techniques, the present interconnect density imposes severe restraints on attempts to reduce the size and increase the complexity thereof. It is highly desirable to provide a method whereby electronic circuits may be provided with extremely narrow conductors, and very narrow spacing therebetween, to realize circuitry having an increased interconnect density and allowing size reduction and increased complexity.